The Stovebolt Site Forums The Shop Area Engine Shop Loose Balancer

I know this has probably been covered before in "The Forums", but I'm not sure my problem is exactly the same. I've read about drilling the crank tip and threading it for a bolt to be used hold the harmonic balancer on, but the harmonic balancer on my engine is loose side to side, not front to back. In other words, it moves about 1/4" to 1/2" back and forth and in so doing, the water (fan) pump moves as does the alternator and a/c compressor. So, it is slipping back and forth, or left and right, on the crankshaft. when idling, it sounds like bottom end internal engine noise. At any amount of RPM's off of idle, there is no noise. Any ideas on how to fix this?

That much wobble is going to require a new balancer, and maybe another crankshaft. You're going to find the inside diameter of the balancer worn, and probably the keyway in the balancer at least twice as wide as it should be. The crankshaft snout will be too badly worn to press-fit another balancer on, so drilling and tapping for the center bolt will be an absolute necessity. If the keyway in the crank snout is wobbled out to the point a Woodruff key is a sloppy fit, it's time to replace the crankshaft.
Jerry

Not sure what a new crank would cost, or even a used one... but grinding/polishing the journals, magnaflux and balance is going to be over $200.

I know they weld up journals... it *might* be cheaper to have the snout welded up/ground to size.

But if your current crank is at the higher side of wear (.040 or .050 under) I would get another. If STD or .020 under I might repair if the cost was similar.

I spent several years running the connecting rod reconditioning department of a machine shop where we specialized in crankshaft welding, straightening, and regrinding. Repairing just the snout of a stovebolt crankshaft would be in the $200.00 range, as two separate operations would be involved. Item #1 will be the Woodruff key slot- - - -inserting a solid copper key and building up the surrounding area with weld material to tighten the clearance, then recutting the slot to accurate dimensions. Then the press-fit area of the crank snout would have to be welded up and ground back to the proper diameter. Then any regrinding and/or polishing of the bearing journals would need to be accomplished. Little if any balancing of an inline 6-cylinder crankshaft is required, since it's almost perfectly balanced by the 120-degree separation of the counterweights. If it is spun up in a balance machine, no bob weights are needed to simulate the weight of connecting rods and pistons like is required with a 4 or 8 cylinder crankshaft.

Stovebolt crankshafts are listed on Ebay every day. Even with shipping, that route would probably be less expensive than major surgery on the snout of the crank in question.
Jerry

Thank's for the 'how to'!

Unless the used crank had papers showing it was fluxed and mic'd its a crap shoot if you will get a good one.